1. Field of the Invention
The present invention relates to a cooling device for a motorcycle, and particularly to a beneficial arrangement of a cooling water pump and a reservoir tank.
2. Description of the Background Art
Japanese Utility Model No. Hei. 5-9995 discloses a motorcycle provided with a skid plate for covering the top and front of a crankcase, and having a pair of left and right water tanks mounted above the skid plate on either side of the crankcase.
A reservoir tank of a motorcycle is a comparatively large and heavy component, and is usually arranged on the side of a rear fender of the vehicle. However, if this is done, it is not possible to check the amount of water while traveling. Also, piping from a radiator is long and is therefore complicated and heavy. In addition, with respect to vehicle layout, the area occupied by the reservoir tank is large which means it is difficult to ensure sufficient piping space. Furthermore, it is difficult to concentrate the mass because the reservoir tanks are arranged away from the center of gravity. Finally, since there are large variations in the posture of the vehicle at comparatively high positions of the vehicle, leakage is likely to occur.
With the above described related art, by using a skid plate, it is possible to make effective use of dead space. However, this water tank is comparatively rigid and since it is intended to be useful as a protection member for the crankcase and as a storage space for drinking water, it will soon become empty and capacity variations are substantial. The object of this invention is to solve the above described problems.
In order to solve the above described problems, the cooling device of the present invention is for a motorcycle with an engine arranged between front and rear wheels, with the lower part of the engine being covered by a shield plate. The engine includes a crankcase at a lower portion thereof, and a cylinder head projecting outward from the top of the crankcase. A cooling water pump for circulating cooling water for the engine is arranged on one side of the crankcase. A reservoir tank for cooling water is arranged close to the other side. At least front parts of the cooling water pump and the reservoir tank are covered by a skid plate.
A skid plate is used, and the cooling water pump and the reservoir tank are arranged so as to be on either side of the crankcase above the skid plate. As a result, piping for respective radiators can be shortened, and it is possible to prevent weight increase by simplifying the piping. Also, by providing the cooling water pump and the reservoir tank above the skid plate, they can be arranged at the lowest position where there are relatively few changes in attitude of the vehicle, which means that leakage can be reduced. Also, even if they are made of a resin material having comparatively low rigidity, it is possible to anticipate protection using the skid plate and to make effective use of dead space.
Also, since the reservoir tank usually maintains an almost constant volume, fluctuation in liquid amount is slight. Further, by arranging the tanks close to the crankcase, the mass can be concentrated promoting a low center of gravity, and a change in the center of gravity is slight. Finally, it is possible to check the liquid amount at any time while traveling.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.